高掺镁铌酸锂晶体OH^-吸收光谱的低温研究  

Study on OH^- Absorption Spectra in Highly Mg-doped Lithium Niobate Crystals at Low Temperature

作　　者：师丽红[1,2] 陈洪建[3] 阎文博[3] 

机构地区：[1]南开大学弱光非线性光子学材料先进技术及制备教育部实验室,天津300457 [2]天津城市建设学院基础部,天津300384 [3]河北工业大学材料科学与工程学院,天津300130

出　　处：《人工晶体学报》2009年第3期803-806,共4页Journal of Synthetic Crystals

基　　金：天津自然科学基金(No.09JCYBJC02400);河北自然科学基金(No.F2009000108);天津市高等学校科技发展基金(No.20070502);河北省教育厅科研计划(No.2008113)

摘　　要：本文测量了纯铌酸锂和高掺镁铌酸锂晶体的低温红外光谱,观察了OH-吸收峰的温度依赖特性。研究发现纯铌酸锂的OH-振动吸收峰基本不随温度而变化,而高掺镁铌酸锂晶体的OH-振动吸收峰的主峰峰位随温度的降低向高波数方向移动。通过分析两种晶体中不同的缺陷模型以及H+在晶格中的占位,我们提出高掺镁铌酸锂晶体中的H+紧邻高电性杂质缺陷(MgNb)3-分布,直接参与缺陷集团,完全不同于纯铌酸锂晶体中H+的分布情形,这造成了高掺镁铌酸锂晶体中OH-振动吸收峰随温度的变化。而集团内部缺陷之间相互作用随温度降低而增强的趋势是OH-振动吸收峰右移的主要原因。The infrared absorption spectra of lithium niobate crystals and highly Mg-doped lithium niobate were measured at low temperature, and the change with the temperature was observed. It was found that the OH^- absorption peak of pure lithium niobate crystals don＇t changed with temperature hut the peak position of OH^- absorption spectra in highly magnesium-doped lithium niobate crystals moves to the high wavenumber with the temperature decreasing. From the analysis of the defect model in two types of crystals and the location of H^＋ there, the above observations were explained. In contrast with the case of pure lithium niobate crystals, the H^＋ directly participant in defect complex and distribute very near the highly-charged impurity defects in highly magnesium-doped lithium niobate crystals, which causes the OH^- absorption peak varies with changing temperature. The increasing interaction between defects in complex is suggested to be the origin of the blue shift of OH^- absorption peak with the decrease of the temperature.

关 键 词：铌酸锂 红外吸收光谱 杂质缺陷 

分 类 号：O437[机械工程—光学工程]